Difference Between 7.62 NATO and .308 Winchester

7.62 NATO vs .308 Winchester
The 7.62 NATO and .308 Winchester rounds are very close to identical with each that many people think that they can be used interchangeably. The main difference between the 7.62 NATO and .308 Winchester rounds is with which rifles you can use them. If you have a modern rifle that shoots .308 Winchester rounds, then it is very likely that you can shoot 7.62 NATO rounds. If you have an old rifle meant to shoot 7.62 NATO rounds, then you should never use .308 Winchester rounds.

The reason why you should never use .308 Winchester rounds in a rifle meant to fire 7.62 NATO rounds is the size of the chamber. The rounds of a .308 Winchester will be too loose inside a 7.62 NATO, This can have terrible results when you fire the round. As the powder detonates, the shell might stretch too much, causing it to rupture and explode. A round exploding in the chamber is a bad situation by all accounts and you will probably ruin your rifle as well as injure yourself. The 7.62 NATO rifles were meant to take military spec bullets that have much thicker shells. Not only does the thicker material make the shell stronger, it also reduces the space inside for the powder.

But if you turn the tables and put a 7.62 NATO round in a .308 Winchester rifle, you should have no problem except for a minor hitch when it comes to the length. Some 7.62 NATO rounds may not fit into the .308 Winchester chamber simply because it is too long. This happens very rarely and many people have used 7.62 NATO rounds for years and have not encountered this problem. This is probably a problem with older rounds and rifles.

If you have a .308 Winchester rifle, you can use either of the two rounds just as both are perfectly usable. But if you own a 7.62 NATO rifle, it is much better if you just stick with the 7.62 NATO rounds. There’s no reason to compromise safety by using the .308 Winchester rounds.
Summary:

1. You can shoot 7.62 NATO cartridges in a .308 Winchester rifle but not the other way around
2. 7.62 NATO rifles may have too much headspace for .308 Winchester rounds
3. Some 7.62 NATO rounds may be too long to fit in a .308